A medical image diagnosis apparatus includes a capturing part for photographing a subject to capture medical images thereof. Examples of such medical image diagnosis apparatus include ultrasonic diagnosis apparatuses, X-ray diagnosis apparatuses, X-ray CT (computed tomography) systems, MRI (magnetic resonance imaging) equipment, and the like.
An ultrasonic diagnosis apparatus has an ultrasonic probe, and transmits/receives ultrasonic waves to/from a subject using the ultrasonic probe to obtain echo images as medical images (ultrasound images).
In many clinical practices, a puncture is performed under ultrasound guidance, in which a puncture needle is rendered in an echo image (see, for example, Japanese Unexamined Patent Application Publication No. 2007-215672).
Among puncture techniques is radiofrequency ablation (RFA). In RFA treatment, for example, a puncture needle having an electrode (electrode needle) is used. The puncture needle is inserted into the body of a subject under ultrasound guidance. When the tip of the puncture needle (needle tip) reaches a cauterization object, current called radio wave is conducted to generate heat around the needle, thereby cauterizing the cauterization object. Hereinafter, cauterization of a cauterization object may sometimes be referred to as “real cauterization”. Besides, the time when the needle tip reaches the cauterization object may sometimes be referred to as “real cauterization time”, and the position of the needle tip at this time may sometimes be referred to as “real cauterization site”.
While the puncture needle is being removed or withdrawn after the real cauterization, cauterization is repeatedly performed just a little each time the needle tip has moved a predetermined distance (e.g., about 1 cm) from the real cauterization site. This procedure may sometimes be referred to as “antiproliferative treatment” or simply as “treatment”. To cauterize a little bit in the treatment may sometimes be referred to as “little cauterization”. In addition, the time when the needle tip has moved the predetermined distance may sometimes be referred to as “little cauterization time”, and the position of the needle tip at this time may sometimes be referred to as “little cauterization site”. Incidentally, “antiproliferative treatment time” includes “little cauterization time”, while “puncture time” includes “real cauterization time” and “antiproliferative treatment time”.
In the puncture as described above, it is difficult to know the length of the predetermined distance (e.g., about 1 cm) under ultrasound guidance, and therefore, it is difficult to make a determination as to whether the needle tip has moved the distance. The operator can measure the predetermined distance by measuring a distance along the puncture needle with a distance measurement mechanism and using this as a guide. However, the measurement by a distance measurement mechanism requires considerable care and time, which leads to prolonged work, and thus imposing a heavy burden on patients as well as operators.